DTC B1244: Light Sensor Circuit Malfunction [10/2014 - 09/2017]: Procedure

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [10/2014 - 09/2017]

   Body Electrical > Main Body > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  2

1. Check for DTCs.

   Refer to DTC CHECK / CLEAR [10/2014 - 09/2017]

   Body Electrical > Main Body > Trouble Codes 

   Result

   Proceed to
   DTC B1244 output does not occur
   DTC B1244 output occurs

Result: 

DTC B1244 output does not occur 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 09/2017] 

Result: 

DTC B1244 output occurs 

See step  3

1. Using the Techstream, read the Data List.

   Refer to DATA LIST / ACTIVE TEST [10/2014 - 09/2017]

   Body Electrical > Main Body > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Light Sensor Illuminance	Light control sensor illuminance	0 to 17600 lx	Value is output according to ambient light level	-

   Body Electrical > Main Body > Data List 

   Tester Display
   Light Sensor Illuminance

   OK

   The display is as specified in the normal condition column.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [10/2014 - 05/2019] 

Result: 

NG 

See step  4

1. Disconnect the I48 main body ECU (multiplex network body ECU) connector.
2. Disconnect the J6 automatic light control sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I48-21 (CLTE) - J6-2 (CLTE)	Always	Below 1 Ω
   I48-19 (CLTB) - J6-1 (CLTB)	Always	Below 1 Ω
   I48-20 (CLTS) - J6-4 (CLTS)	Always	Below 1 Ω
   I48-21 (CLTE) - Body ground	Always	10 kΩ or higher
   I48-19 (CLTB) - Body ground	Always	10 kΩ or higher
   I48-20 (CLTS) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

1. Remove the instrument panel junction block assembly and main body ECU (multiplex network body ECU) as a unit with the connectors still connected.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (Main Body ECU [Multiplex Network Body ECU])

   Refer to REMOVAL [10/2014 - 05/2019]

2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   I48-19 (CLTB) - I48-21 (CLTE)	Engine switch off	Below 1 V
   	Engine switch on (IG)	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [10/2014 - 05/2019] 

Result: 

OK 

See step  6

1. Check the automatic light control sensor.

   Refer to INSPECTION [10/2014 - ]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [10/2014 - 05/2019] 

Result: 

NG 

REPLACE AUTOMATIC LIGHT CONTROL SENSOR. Refer to  REMOVAL [10/2014 - ]